1. Field of the Invention
The present invention relates to a gas sensor element and a gas sensor for detecting the concentration of a specific gas in gaseous environment, and a control system of the gas sensor.
2. Description of the Related Art
Hitherto, for detecting the concentration of oxygen in the exhaust gas from an internal combustion engine of a motor vehicle, various types of gas (viz., oxygen) sensors have been proposed and put into practical use. Some of them are of a type that uses a gas sensor element which comprises a cell including a solid electrolyte body of zirconia or the like and a pair of electrodes having the solid electrolyte body intimately put therebetween. The concentration of a specified gas is detected based on current flowing between the electrodes through the solid electrolyte body.
As is known, the gas sensor elements are those that tend to show variations in output caused by variations in production. For compensating the variations in the output of sensor elements, various measures have been proposed, one of which is shown in Japanese Laid-open Patent Application (Tokkaihei) 9-15201.
In the measures shown in the publication, there are provided a resistor that is provided on a surface of a ceramic substrate to serve as a detecting section and a voltage-dividing resistor (or compensating resistor) that is connected to the detecting resistor in parallel. By applying a LASER trimming to the voltage-dividing resistor, the value of the resistance (or resistance value) is adjusted. With such measures, a plurality of sensor elements produced are able to exhibit even outputs.